pci: Remove unnecessary 'default n' from Kconfig

'default n' is the default anyway so it doesn't need to be specified
explicitly, and the rest of the file doesn't specify it either anywhere.
Drop it.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

drivers/pci/Kconfig

@@ -35,7 +35,6 @@ config PCI_PNP
 
 config PCIE_DW_MVEBU
 	bool "Enable Armada-8K PCIe driver (DesignWare core)"
-	default n
 	depends on DM_PCI
 	depends on ARMADA_8K
 	help